It usually happens that after an electronic device is connected to a power source if a great difference occurs between the phases of voltage and current of input power, a great portion of power will be stored in capacitor or inductor elements and result in the actual power (output power) lower than the input power. In order to increase output power efficiency and reduce ineffective power, most power supplies at present have a power factor correction circuit to regulate the voltage phase and current phase of the input power to make them coincided as much as possible to get a greater actual power. The power factor correction circuit can be divided into an active type and a passive type. The active type power factor correction circuit mainly includes a control unit, a switch and an energy storage coil. The control unit determines ON time series of the switch to alter the current ON period of the energy storage coil. Thus the input power passing through the power factor correction circuit can be regulated to attain approximate one for the power factor (the power factor is one when the voltage phase is the same as the current phase). The conventional lighting equipment generally are not equipped with the power factor correction circuit, thus have lower power efficiency. The so called “power saving lighting features” nowadays mostly get power of a higher power factor through an electronic ballast circuit. The electronic ballast circuit generally includes a power factor correction circuit to regulate the phase difference of current and voltage and a transformer or inverter to transform current amount or voltage level to energize lighting bulbs. For instance, R.O.C. patent publication No. 200701295 entitled “Electronic ballast for power factor correction devices with continuous current” provides a circuit structure including a power factor correction device and an inverter. Another R.O.C. patent No. M312155 entitled “Electronic ballast for high pressure gas discharging lamps” discloses an electronic ballast with a power factor correction circuit. Input power of the electronic ballast passes through the power factor correction circuit and a full bridge driving circuit to be rectified, then is output through a voltage boosting circuit. However, on the conventional circuits mentioned above a transformer (inverter) or a voltage boosting circuit has to be provided to transform the voltage or current after it has passed through the power factor correction circuit. As a result, a greater loss incurs, and the number of elements needed also increases (could be a two-stage or three-stage circuit). And the product size also is bigger, and the cost is higher.